In this period of obvious natural emergence of viral and other diseases, it is unclear as to what diseases are emerging, why they are emerging, and what, if anything, can be done to prevent or diminish their impact. This book, a compendium of presentations made at an international meeting of experts, provides summaries of areas of concern and details as to how disease agents such as Nipah and Hendra viruses in Australasia and West Nile virus in the Americas might have suddenly appeared. Either by alterations in natural habitats and diversity or by chance, pathogens emerge from time to time. This book addresses various aspects of such emergences, such as pathogenetic mechanisms of viruses, diagnosis of viral infections, viral host-management strategies, viral genetics, vaccine development and application. It is especially valuable for laboratory virologists, disease ecologists, physicians, and those who want to understand the complexities of viral characteristics.